以虎跳门特大桥作为工程背景 ,采用梁段单元法建立了大跨度连续刚构桥预应力混凝土箱形梁极限承载力分析的数学模型 ,并推导出薄壁箱梁的 U.L.列式增量平衡方程。在研究中 ,考虑了箱梁顶板、底板和腹板局部变形的影响及材料非线性和几何非线性。按形成矩阵的“对号入座”法则导引出非线性薄壁箱梁单元刚度特性矩阵 Based on the engineering background of Hujianomen Bridge, the mathematical model for the analysis of ultimate bearing capacity of prestressed concrete box girders for long-span continuous rigid frame bridge is established by using the beam segment method and the UL increment of thin-walled box girder Balance equation. In the study, the influence of local deformation of box girder roof, bottom plate and web and material nonlinearity and geometric nonlinearity were considered. According to the formation of matrix “condemnation” rule leads to the nonlinear thin-walled box girder stiffness characteristics matrix